Process for manufacturing a type-carrying printing belt

ABSTRACT

A process for fabricating an endless type-carrying belt for an on-the-fly printer, wherein open belt portions are first prepared with type-carrying tongue portions defined along the length thereof, each of said tongue portions bearing a stud wherein a raised character is formed in each stud by coining by rolling, and wherein said open belt portions have the ends thereof joined together to form an endless belt.

United States Patent [191 [451 Apr. 3, 1973 Picard [54] PRGCESS FOR MANUFACTURING A TYPE-CARRYING PRINTING BELT [75] Inventor: Michel Picard, Belfort, France [73] Assignee: Societe Industrielle Honeywell Bull (Societe Anonyine), Paris, France [22] Filed: Sept. 8, 1971 [21] Appl. No.: 178,663

[30] I Foreign Application Priority Data 11 1970 Ernst ..148 127x 4 1971 McDowell ..101 111 Primary Examiner-J. Spencer Overholser Assistant Examiner-Richard Bernard Lazarus Attorney-. -Ronald T. Reiling -[57] ABSTRACT A process for fabricating an endless type-carrying belt for an on-the-fly printer, wherein open belt portions are first prepared with type-carrying tongue portions defined along the length thereof, each of said tongue portions bearing a stud wherein a raised character is formed in each stud by coining by rolling, and wherein said open belt portions have the ends thereof joined together to form an endless belt.

11 Claims, 9 Drawing Figures PATENIEDAPR 3 m5 SHEET 1 OF 2 Tor PROCESS FOR MANUFACTURING A TYPE- CARRYING PRINTING BELT BACKGROUND OF THE INVENTION PV 174,294, filed Nov. 19, 1968 for Endless Type 1 Support Band for Movable-Type Printing Machine.

It is known that such an endless belt, in the printer in question, is stretched over two pulleys which drive it with a high linear velocity. It must be capable of resisting the repeated shocks of the print hammers and must also provide a long life of service in order that it maintain its advantages of economical cost compared with other kinds of type-carrying supports, such as type-carrying drums.

On the other hand, it is necessary that the raised type characters, each carried by a respective tongue alongside of one edge of the belt, be positioned with a high degree of precision in relation to a series of reference holes aligned parallel to and near the other edge of the belt. Briefly, a high degree of dimensional precision of the entire type-carrying belt is essential in view of its interchangeability, on one hand, and for proper operation of the printer, on the other hand.

Therefore, it is an object of the present invention to provide processes for fabricating an endless type-carrying belt which has both a high degree of dimensional precision and suitable longevity, in as economical a manner as possible. To attain this object, numerous problems difficult of resolution are encountered. One of these problems, which appears of critical importance is the operation of forming the raised characters, because the quality of these characters must be the highest possible. It has been decided to proceed with the formation of these characters by rolling using a matrix before the endless belt is formed; i.e., when it is still in the form of a flat band of predetermined width and length. This also facilitates the prior formation of studs separated and spaced apart with a pitch P at the locations where the raised type characters must be provided. It has also been deemed advantageous to not cut out the slots separating the type-carrying tongues until after the formation of the endless belt; i.e., after joining end-to-end the extremities of the belt which has been made of proper length.

It is possible to fabricate the endless belt by means of two half-belts, which offers the advantage that the tooling and coining by rolling are less expensive and less cumbersome since their length maybe reduced to nearly one-half, the only consequent disadvantage being the additional end-to-end welding required to obtain the endless belt.

SUMMARY OF THE INVENTION Therefore, the instant invention provides a process for fabricating an endless metallic type-carrying belt intended for use with an on-the-fly printer, such belt having a plurality of parallel elongated tongues along one of its edges, each tongue being provided with a printing type character in relief. The process of the invention comprises: (a) fabricating one (or two) profiled belts of predetermined width and generally of the required final thickness, having an increased thickness in the zone of the characters, provided with oblong slots cut with pitch P to leave between two adjacent slots a stud of predetermined size, and provided with a return hole and a reference hole in alignment with each slot; (b) coining by rolling of the belt(s) for progressively forming on each stud a printing type character in relief; (c) cutting the belt(s) to a predetermined length; (d) welding end-to-end the ends of the belt(s) to form an endless belt; (e) cutting out the final slots to the return holes to define the final form of the type-carrying tongues; and (f) shearing off the portion of the belt extending beyond the useful extremities of the type-carrying tongues.

According to a first version, when starting with a metal belt of thickness corresponding to that of the planned studs, the first phase of operations (a) consists of profiling the belt, either by mechanical removal or by chemical or electrolytic machining until the desired general thickness is obtained, followed by cuttingpunching the slots, the return holes and the reference holes by indexing on a reference pitch.

According to a second version, after the preparation of the belt(s) of desired width and thickness, and of a sufficient number of studs of suitable form, the first phase of operations (a) consists of cutting-punching the primitive slots, the return holes and the reference holes in the belt(s) by indexing on a reference pitch, and the electrical welding to the belt, preferably by diffusion, of the studs, one stud on each portion of the belt subsisting between adjacent slots.

BRIEF DESCRIPTION OF THE DRAWING The invention will be described with reference to the accompanying drawing, wherein:

FIG. 1 is a perspective view of an endless type-carry? ing belt intended for mounting on two pulleys of a printer;

FIGS. 2A and 2B are transverse cross-sectional views of a rough-shaped belt obtained in a first phase of operations in accordance with respective first and second versions;

FIGS. 3A and 3B are elevational views of the portions of the belt having slots and holes corresponding to the respective first and second versions of FIGS. 2A and 2B;

FIG. 4 is an elevational view of a portion of the belt after the type characters have been coined by rolling;

FIG. 5 is an elevational view of a portion of the belt after cutting out of the slots defining the outlines of the type-carrying tongues, and

FIGS. 6A and 6B are transverse cross-sectional views of a damping strip of known type in accordance with respective first and second variations.

DESCRIPTION OF THE PREFERRED EMBODIMENT The endless type-carrying belt 10, of known kind, is shown in its finished state in FIG. I mounted ,in a printer on two pulleys. These two pulleys, not shown, have vertical axes of rotation 11 and 12. Belt 10 is provided along its entire upper edge with type-carrying tongues 13. All of tongues 13 are identical and spaced apart with a pitch P, for example of 3.91 mm.

FIG. 1 illustrates that type-carrying belt is preferably comprised of two half-belts 10-1 and 10-2, which clearly entails the presence of two seams l4 and 15, each seam being disposed on the axis of a slot separating two adjacent tongues 13.

In an embodiment considered, if belt 10 must be provided with several complete sets of different characters, for example eight sets of 48 different characters or symbols, the minimum length of each half-belt must be 750.72 mm.

Belt 10 is provided towards its lower edge with reference holes 16, each of holes 16 being exactly aligned with the axis of a slot separating two adjacent type-carrying tongues 13. Holes 16 serve, in known manner, to synchronize the strikings during printing.

The printing type characters appear on the external face of belt 10 because it is assumed that in front of the front portion of the belt are disposed an ink or carbon ribbon, a print-receiving member in the form of at least one wide strip of paper, and finally a series of print hammers selectively actuable in known manner. As described in the above-mentioned patent application, the ends of the type-carrying tongues 13 pass in front of and in contact with a fixed platen or anvil, not shown, and along the length of the print line. The linear speed of the belt may be approximately 6 m per second.

Among the operations constituting the fabrication process of the invention, the initial sequence of operations may assume two different versions, each having respective advantages and disadvantages.

According to the first version, to which FIGS. 2A and 3A relate, belts 17 are prepared with a slightly greater length than indicated previously herein, with a width of 70 mm, for example, and a thickness of E2. These belts may be preferably of hardened structural steel, such as that containing essentially, in addition to iron, 18 percent nickel, 8 percent cobalt and 5 percent molybdenum. A first machining is intended to produce a stud 18 of trapezoidal form centered on an axis 19, which is the axis on which the raised printing type characters subsequently will be aligned. This machining which will reduce the greater part of the width of the belt to the thickness El may be effected by grinding or by a known chemical or electrolytic process. The thickness El may be 0.15 mm, for example.

Next, the cutting-punching, with pitch P, of primitive slots 20 (FIG. 3A), return holes 21, and reference holes 16 is carried out with a set of tools selected for this purpose. Each slot 20 comprises an upper portion having a width which leaves a remaining stud of 1.35 mm width and a lower portion of lesser width. Each hole 21 coincides with the lower part of a completed slot, such as shown in FIG. 5. Holes 21 and 16 have respective diameters 1.95 mm and 1.5 mm, for example.

According to the second version, to which FIGS. 28 and 38 relate, two belts 22, of adequate length, of 70 mm width, and of thickness El are prepared to provide a type-carrying belt 10. Also prepared are 384 studs 23, each having a thickness equal to E2-El. Studs 23 may be fabricated on a combined cutting-stamping tool. Belts 22 may be prepared from commercial laminated strips having a predetermined amount of hammerhardening. These belts are formed by the cuttingpunching of the primitive slots 20, the return holes 21, and the reference holes 16, all relative to the pitch P.

Then, studs 23 are attached to the cutout belts 22 by electrical welding on a special tool and machine. The recommended welding process is that termed by diffusion. This process differs from welding by the common Joule effect in that the pressure applied by the electrodes on the pieces to be welded is greater and the current intensity passing through the pieces is less, although the time during which current flows is longer. The welding electrodes may be coiled by circulation of water and, if it is desired to provide rapid welding, the pieces to be welded can be immersed in cold water.

The advantages of this welding process are the conservation of the materials mechanical characteristics resulting from the hammer-hardening, as well as the preservation of the dimensions of the welded pieces because their temperature always remains less than that which causes annealing of the metal,

Comparing the above-described two versions of the initial sequence of operations, the first version provides an assurance of complete cohesion of the raised type characters to their tongues, and, therefore, a very high resistance to shock. Further, this version does not produce deformation of the belt in its plane. As disadvantages are the necessity of subsequentlyv following the above-mentioned operations by an electrolytic polishing operation and, in addition, the fact that the amount of metal removed during profiling may adversely influence the cost of fabrication because the steel utilized is relatively expensive.

Included among the advantages of the second version are economy due to the absence of metal waste, the possibility of utilizing different steels for the belts of thickness El and for the welded studs, greater precision of the belt thickness E1, and improved characteristics by virtue of the hammer-hardening which are also favorable to further operations. This version may give rise to some unfavorable factors, such as the edgewise deformation of the belt at the time of the cutting operations (necessitating a later straightening) and the possibility that a small number of the raised type characters will become loose as a consequence of the repeated shocks during printing.

However, whichever version is employed through this phase for realizing the sequence of operations (a), the subsequent operations will be identical.

The next operation (b) is directed to providing the raised type characters on the two half-belts as shown by FIG. 4. The tools to be employed include a matrix in the form of a cylindrical drum on the periphery of which are impressions corresponding to a set of characters or symbols, which are engraved intaglio. One strip bearing the rough-shaped studs (in accordance with FIGS. 3A or 3B) is placed between this matrix and a horizontal bed, which may be driven with a reciprocating movement. The belt is positioned precisely on the bed. The matrix, turning on a horizontal axis, is urged with a very great force against the belt and turns to follow the belt as it is alternately displaced alongits entire length. During the successive reciprocating movementsof the belt, the matrix is progressively brought closer to the bed, so that ultimately all of the type characters are formed in the course of this operation of progressive coining by rolling. The appearance of a portion of the belt is then that shown by FIG. 4. FIG. 4 shows that each stud 18 or 23 has been flattened, which modifies,

as at reference numeral 24, the form of primitive slots 20, since all of the belt has been reduced to the thickness E1 of 0.15 mm with the exception of the type characters in relief. It is to be noted that the thickness E2 is, for example 0.7 mm (FIGS. 2A and 28).

It' is apparent that it is advantageous to limit the length of the machine for coining by rolling. This is the sole reason that favors the utilization of two half-belts joined to obtain the final endless belt.

The next operation (c) consists of cutting each halfbelt to exact length by any suitable procedure. A halfhole 21 must be found at each end, and the length is 750.72 mm, as described above.

The operations which ensue are the following:

The operation (d) is for forming an endless belt by welding end-to-end the two ends of the two half-belts. This welding is performed preferably by microplasma, a known process of arc welding with wellregulated current, which results in a very good welded seam without deformation of the welded pieces.

The operation (e) consists of cutting out with a press the final slots 25 between the type-carrying tongues,

such as those which are shown in FIG. 5. The form of these slots is such that they leavea portion of rectangular form, of which the width may be 2.5 mm, around each of the raised type characters.

The two preceding operations may be executed in the described order or in reverse order.

Then, the final necessary operation (f) is the separation of the upper strip 26. This separation is effected by shearing with any suitable tool at the level 27 that corresponds to the upper part of the above-mentioned rectangular portions of the type-carrying tongues. The

' endless type-carrying belt then assumes the appearance shown by FIG. 1.

Certain other operations can be intercalated between the above-described operations (e) and (f) or (d) and (f).

For example, it may be useful to reduce the structural hardness of the endless belt by a suitable thermal treatment. If the steel described previously herein is utilized, this thermal treatment consists of heating in a neutral atmosphere to 480 C for 3 hours, which causes virtually no deformation of the type-carrying belt.

A surface treatment may be useful also to-increase the surface hardness of the belt, which results in a greater resistance of the type-carrying tongues to the shocks and the deformations. This operation consists of bombarding with jets of glass micro-balls, by means of directed nozzles, the two faces of the endless belt.

Finally, if according to the teachings of the abovementioned patent application the type-carrying belt is provided with a viscous damping strip, the mounting of this strip must be effected before the shearing operation (f).

This strip 28, of rectangular cross-section, is shown in FIG. 5 by broken lines. Strip 28 may be positioned a few millimeters below the level 19 of the type characters.

According to the structure of this strip it may be attached by molding, as for example strip 28-1 shown in FIG. 6A. Strip 28-1 may be composed of an elastomer, of the synthetic rubber type, or of a polyurethane. Strip 28-1 may consist of two continuous portions which can be of different thickness on both sides of tongues l3.

According to a variation shown in FIG. 6B, strip 28-2 may consist of only a single continuous portion, in which instance it can be attached by any suitable process; i.e. by cementing, etc., preferably onto the face of the tongues where the raised type characters are found.

Particular care must be taken in the machining. The problem lies in the punching of the reference holes 16 which fall on the welded seams 14 and 15 (FIG. 1). These particular holes, which are spaced apart 750.72 mm along the two half-belts 10-1 and 10-2, must not be punched when the sequence of operations (a) are performed and, particularly, the cutting-punching. Such holes should be added only after the operation (d) in which the half-belts are welded end-to-end. They will be provided by drilling or punching, for example before the operation (e) of cutting out the final slots 25.

By virtue of the sequence of operations or steps which have been described herein, it is possible to provide an endless type-carrying belt of very great dimensional precision, particularly relative to the rigorous observance of the pitch P spacing of the printing type characters and their positioning relative to reference holes 16 and to the lower edge of the endless belt. The type-carrying belt has the further advantage of possessing a very high resistance to mechanical stresses and, consequently, has a satisfactory service life.

What is claimed is:

1. A process for fabricating an endless metallic typecarrying belt for use with an on-the-fly printer, said belt having a plurality of parallel elongated tongues along one of its edges, each of said tongues bearing a raised printing type character, said process comprising the steps of:

a. fabricating at least one profiled belt of predetermined width and generally of the required final thickness, said belt having an increased thickness in the vicinity of the type characters, having oblong slots cut out with a pitch P to leave between adjacent ones of said slots a stud of predetermined size, and having a return hole and a' reference hole in alignment with each stud;

. coining by rolling each of said belts for progressively forming a raised type character on each stud;

. cutting each of said belts to a predetermined length;

. welding together the ends of each of said belts to form an endless belt;

. cutting out the final slots to define the final form of the type-carrying tongues, and

f. shearing off the portion of the belt extending beyond the useful extremities of said type-carrying tongues.

2. The process of claim 1, wherein said process commences by utilizing at least one metal beltof thickness corresponding to that of the desired studs, and wherein said step (a) comprises profiling each of said belts by one of mechanical removal, chemical machining, and electrolytic machining until a desired general thickness is obtained, followed by cutting-punching said slots, said return holes and said reference holes.

3. The process of claim 1, wherein said process commences by utilizing at least one belt of desired width and thickness and a sufficient number of studs of suitable form, and wherein said step (a) comprises cuttingpunching said slots of primitive form, said return holes, and said reference holes into said belts, and electrically welding said studs to said belts by diffusion, one stud to each portion of said belt subsisting between adjacent slots. 7

4. The process of claim 2, wherein following said cutting-punching of said step (a) each of said belts is electrolytically polished.

5. The process of claim 2, wherein following said cu ting step (e), each of said belts is subjected to a thermal treatment in neutral atmosphere for reducing the structural hardness of said belts, and a bombardment with jets of glass micro-balls for increasing the surface hardness of said belts.

6. The process of claim 3, wherein following said cutting steps (e), each of said belts is subjected to a thermal treatment in neutral atmosphere for reducing the structural hardness of said belts, and a bombardment with jets of glass micro-balls for increasing the surface hardness of said belts.

7. The process of claim 5, wherein following said bombardment and prior to step (f), a continuous damping strip is solidly attached by one of cementing and molding operations to said type-carrying tongues below the ends of said tongues.

8. The process of claim 6, wherein following said bombardment and prior to step (f), a continuous dampllL-I strip is solidly attached by one of cementing and molding operations to said type-carrying tongues below the ends of said tongues.

9. The process of claim 1, wherein said welding together of said belt endsis effected by microplasma. I

10. A process for fabricating an endless metallic type-carrying belt for use with an on-the-fly printer, said belt having a plurality of parallel elongated tongues along one of its edges, each of said tongues bearing a raised printing type character, said process comprising the steps of:

a. fabricating at least one profiled belt portion of predetermined width and generally of the required final thickness, said belt portion having enclosed elongated slots cut out with a uniform pitch therebetween and having a raised portion of predetermined size between each adjacent pair of said slots; t

. progressively forming a type character in relief on each of said raised portions;

. cutting said belt portion at each of said slots to define the final form of the type-carrying tongues; and

d. shearing off said belt portion beyond said type characters.

11. The process of claim 10, wherein each end of said belt portion is welded to another end to form an endless belt. 

1. A process for fabricating an endless metallic type-carrying belt for use with an on-the-fly printer, said belt having a plurality of parallel elongated tongues along one of its edges, each of said tongues bearing a raised printing type character, said process comprising the steps of: a. fabricating at least one profiled belt of predetermined width and generally of the required final thickness, said belt having an increased thickness in the vicinity of the type characters, having oblong slots cut out with a pitch P to leave between adjacent ones of said slots a stud of predetermined size, and having a return hole and a reference hole in alignment with each stud; b. coining by rolling each of said belts for progressively forming a raised type character on each stud; c. cutting each of said belts to a predetermined length; d. welding together the ends of eaCh of said belts to form an endless belt; e. cutting out the final slots to define the final form of the type-carrying tongues, and f. shearing off the portion of the belt extending beyond the useful extremities of said type-carrying tongues.
 2. The process of claim 1, wherein said process commences by utilizing at least one metal belt of thickness corresponding to that of the desired studs, and wherein said step (a) comprises profiling each of said belts by one of mechanical removal, chemical machining, and electrolytic machining until a desired general thickness is obtained, followed by cutting-punching said slots, said return holes and said reference holes.
 3. The process of claim 1, wherein said process commences by utilizing at least one belt of desired width and thickness and a sufficient number of studs of suitable form, and wherein said step (a) comprises cutting-punching said slots of primitive form, said return holes, and said reference holes into said belts, and electrically welding said studs to said belts by diffusion, one stud to each portion of said belt subsisting between adjacent slots.
 4. The process of claim 2, wherein following said cutting-punching of said step (a) each of said belts is electrolytically polished.
 5. The process of claim 2, wherein following said cutting step (e), each of said belts is subjected to a thermal treatment in neutral atmosphere for reducing the structural hardness of said belts, and a bombardment with jets of glass micro-balls for increasing the surface hardness of said belts.
 6. The process of claim 3, wherein following said cutting steps (e), each of said belts is subjected to a thermal treatment in neutral atmosphere for reducing the structural hardness of said belts, and a bombardment with jets of glass micro-balls for increasing the surface hardness of said belts.
 7. The process of claim 5, wherein following said bombardment and prior to step (f), a continuous damping strip is solidly attached by one of cementing and molding operations to said type-carrying tongues below the ends of said tongues.
 8. The process of claim 6, wherein following said bombardment and prior to step (f), a continuous damping strip is solidly attached by one of cementing and molding operations to said type-carrying tongues below the ends of said tongues.
 9. The process of claim 1, wherein said welding together of said belt ends is effected by ''''micro-plasma.''''
 10. A process for fabricating an endless metallic type-carrying belt for use with an on-the-fly printer, said belt having a plurality of parallel elongated tongues along one of its edges, each of said tongues bearing a raised printing type character, said process comprising the steps of: a. fabricating at least one profiled belt portion of predetermined width and generally of the required final thickness, said belt portion having enclosed elongated slots cut out with a uniform pitch therebetween and having a raised portion of predetermined size between each adjacent pair of said slots; b. progressively forming a type character in relief on each of said raised portions; c. cutting said belt portion at each of said slots to define the final form of the type-carrying tongues; and d. shearing off said belt portion beyond said type characters.
 11. The process of claim 10, wherein each end of said belt portion is welded to another end to form an endless belt. 